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the air paited very regularly from one body to the 
other at each ftroke, inftead of palling thro’ the pipe 
into the boiler, as imagined. By this, the caufe of 
deception was evident ; which I was ftill in hopes 
of remedying, by having a new pair of bellows 
made, fomewhat larger, and much ftronger. When 
this was fixed, and the engine worked a few firokes, 
I was furprifed to find the bellows did not come 
down, but remained fully charged with air, tho’ it 
had 4.00 lb. weight upon it ; and that, on increafing 
the weight gradually to 1 400 lb. which was as much 
as the bellows could fupport, the air was not forced 
thro’. 
I alfo made feveral experiments, by lowering the 
horizontal pipe two feet under the furface of the 
water, and railing it at different times to within four 
inches of the furface, and could not at any depth 
force the air thro’, whilft the engine worked j but on 
opening the fteam-pipe, which is a pipe for letting 
the fteam pafs from the boiler whenever the engine 
flops, the bellows could then readily force the air 
thro’, tho’ the water boiled ever fo ftrong, and feem- 
ingly made a furprifing increafe of fteam. 
I had the leaden pipe to convey the air from the 
bellows, which was firft put thro’ the top into the 
boiler, carried on the outfide, and palled horizontally 
into it, about the height the water generally Hands, 
that by opening a cock, fixed for the purpofe clofe to 
the boiler, I could readily difcharge all the fteam 
lodged in the pipe ; and by Hunting the cock, and 
making fmall holes at three or four inches diftance, 
I could almoft find the point, where the air and 
fteam met in oppofition, cool air being ftrongly ex- 
pelled thro’ one, and hot fteam thro’ the other. 
It 
